1. Field of the Invention
The present invention relates to a side support device which supports the body of an occupant embracingly from both sides thereof in a seat, especially in a seat for a vehicle such as an automobile and the like.
2. Description of the Prior Art
A conventional vehicle seat such as an automotive seat of a type having two raised side portions is provided with a so-called side support device which is adapted to adjust the distance between the two raised side portions so as to vary the amount of support with respect to the side portions of the body of an occupant of the seat.
An example of the conventional seats equipped with this type of side support device is disclosed in Japanese Utility Model Publication No. 31,504 of 1979.
Specifically, as shown in FIG. 6, in the disclosed conventional seat, in the two side sections (1a)(1b) of a frame member (1) disposed in the back of the seat, there are mounted two raisedly formed support members (2) and (3) in such a manner that they can be rotated inwardly and outwardly, respectively. And, the two support members (2) and (3) can be rotated by an operation mechanism (not shown) comprising screw members and the like so as to adjust the distance between the two raised portions (a1)(a2) of the seat.
In such conventional seat side support device, however, since only the two raised side portions (a1)(a2) are changed with the rotation of the two support members (2) and (3), the side portions of the body of the occupant (b) can be indeed supported, but the intermediate portions (b1)(b2) disposed between the body side portions and the back portions of the occupant can be adjusted little in support so as to provide insufficient holding. Therefore, the above-mentioned conventional seat has a disadvantage that it cannot provide a comfortable sitting touch to the occupant.